Fuel injection device for internal combustion engines



B. BISCHOF May 1, 1934.

FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES Filed March 9, 1933 2 Sheets-Sheet l Jnren/or:

May 1, 11934. I B. BISCHOF H9567@6 I FUEL INJECTION DEVICE FOR INTERNAL-COMBUSTION ENGINES Filed March 9, 1933 2 Sheets-Sheet 2 Jnyen or Patented May 1, 1934 UNITED STATES FUEL INJECTION DEVICE FOR. INTERNAL GOIMBUSTION ENGINES Bernhard Blschof, Winterthur, Switzerland Application March 9, 1933, Serial No. 660,158 In Switzerland March 10, 1932 3 Claims. (01. 103-154) The pump bodies of known fuel injection devices are usually mounted into a casing made of light metal. Such arrangements have the disadvantage that in consequence of remaining de- 5 formation of the light metal casing after mounting the pump bodies several times into the casing, leakages take place to the exterior and therefore the accuracy of the moment at which the suction and pressure strokes begin is lost. Furthermore, the adjustment of the regulating device of such pumps is a difiicult matter, as these regulating members are housed quite in the interior of the pump casing.

The invention refers to a fuel injection device and provides a means of avoiding these disadvantages. According to the invention, the pump 4 bodies are mounted into a special plate made of material with qualities suitable for this purpose; this plate together with the pump bodies forms a unit which is fixed to the pump casing in such a way that it can easily be replaced.

A constructional form of the invention is shown in the drawings.

Fig. 1 shows in a sectional view a pump of 4 known design.

Fig. 2 is a cross section of the pump shown in Fig. 3.

Fig. 31s a longitudinal section, of a pump according to the invention.

The letter (a) represents in the figures the pump casing, (b) the common plate for the pump bodies (0), made by way of example of steel. (d) is a casing containing liquid which serves when compressed as a spring. In addition to this 35 spring of liquid, a steel spring acts upon the counter piston (1c). According to the Figs. 2 and 3, the casing (d) is screwed to the pump body whilst in Fig. 1 said casing is fixed to the pump body by means of a nut (12) The pump body as shown in Figs. 2 and 3 has a round flange (i) which abuts upon the underside of the plate (b) after the conical part (I) of the pump body (0) has been mounted firmly into the plate (b) by means of the threaded portion of the casing (d) which has the shape of a nut and the lower face (g) of which makes contact with the upper side of the plate (1)). Leakages of liquid to the exterior are hereby impossible and the pump body is drawn into the conical hole' of the plate (b) each time the same amount, thereby placing the pressure channel (h), the suction channel (2') and the counter piston (it) each time into the same position with respect to the driven piston (l) the suction line (3) and pressure line (t), provided in the plate (b). According to the arrangement of Fig. 1, the conical part of the pump body (0) is mounted direotlyinto the casing (a) and is fixed into position by the nipple (m) which contains the pressure line. In consequence of the compressibility of the material of the light metal cas- '30 ing (a), the pump body"(c) after several times fits deeper and deeper into the slightly conical hole of the pump body, changing the position of the suction channel (2') and pressure channel (71.) with respect to the driven piston (l) and thereby the beginning of the suction and injection period. If even at the first assembling to Fig. 1 v the pump body fits tightly into the casing, and the nipple (m) snugly into the..hole provided in the pump body, a certain play will take place between the pump body and the conical hole in the pump casing after repeated mounting and dismantling thereby causing losses of fuel to the exterior. This disadvantage is avoided by a design according to Figs. 2 and 3.

With respect to the adjustment of the regulating device, this adjustment is made difficult in the arrangement according to Fig. 1 as the pump casing is completely closed at the top. On the contrary to this design the pump casing according to Figs. 2 and 3 is open on the top and at least on one length side, thereby rendering the mounting of the regulating gear wheels (0) into the regulating rack, very easy.

What I claim is: I

1. In fuel injection devices in combination pump-bodies, a common plate said pump bodies being of conical shape for fitting into conical holes of said common plate, a stop on the pump bodies for allowing the conical pump bodies to fit into said conical holes of said plate, only so far that a tight fit is attained, a pump casing to which said common plate is fixed, spring casings screwed onto said pump bodies for drawing the pump bodies into said holes, driven and counter pistons in said pump bodies, said stop and said spring casings abutting upon the under and the upper sides of said plate adapted to prevent the liquid from leaking to the outside.

2. In fuel injection devices in combination pump bodies, a common plate, said pump bodies being of conical shape for fitting into conical holes of said common plate, suction and delivery channels in said pump bodies, a round flange on the pump bodies rectangular to the pump axes, suction and delivery channels in said common plate, said round flange adapted to allow the conical pump bodies to fit into said common plate only so far that a tight fit is attained and the corresponding suction and delivery channels in the pump bodies and the common plate to register with one another, a pump casing to whichsaid common plate is fixed, spring casings screwed onto said pump bodies for drawing the latter into said holes, driven and counter pistons in said pump bodies, said round flange and said spring casings abutting upon the under and upper sides of said plate adapted to prevent liquid from leaking to the outside.

3. In fuel injection devices in combination, pump bodies, a common plate, said pump bodies being of conical shape for fitting into conical holes of said common plate, suction and delivery channels in said pump bodies, a round flange on the pump bodies, rectangular to the pumpaxis, suction and delivery channels in said common plate, said round flange adapted to allow the conical pump bodies to fit into said common plate only so far that a tight fit is obtained and the corresponding suction and delivery channels in the pump bodies and the common plate to register with one another, a pump casing to which said common plate is fixed, the top and one side of said pump casing having openings adapted to facilitate the adjustment of the regulating gear wheels into the common rack and to improve the accessibility of these members, spring casings screwed onto said pump bodies for drawing the latter into said holes, driven and counter pistons in said pump bodies, said round flange and said spring casings abutting upon the under and upper sides of said plate adapted to prevent liquid from leaking to the outside.

BERNHARD BISCHOF. 

